<?php
error_reporting(E_ERROR | E_PARSE); 

function & XML_unserialize(&$xml){    
    $xml_parser = new XML();    
    $data = &$xml_parser->parse($xml);    
    $xml_parser->destruct();    
    return $data;    
}    

function & XML_serialize(&$data, $level = 0, $prior_key = NULL){    
    if($level == 0){ ob_start(); echo '<?xml version="1.0" ?>',"\n"; }    
    while(list($key, $value) = each($data))    
        if(!strpos($key, ' attr')) #if it's not an attribute   
            #we don't treat attributes by themselves, so for an emptyempty element    
            # that has attributes you still need to set the element to NULL    
  
            if(is_array($value) and array_key_exists(0, $value)){    
                XML_serialize($value, $level, $key);    
            }else{    
                $tag = $prior_key ? $prior_key : $key;    
                echo str_repeat("\t", $level),'<',$tag;    
                if(array_key_exists("$key attr", $data)){ #if there's an attribute for this element   
                    while(list($attr_name, $attr_value) = each($data["$key attr"]))   
                        echo ' ',$attr_name,'="',htmlspecialchars($attr_value),'"';   
                    reset($data["$key attr"]);   
                }   
 
                if(is_null($value)) echo " />\n";   
                elseif(!is_array($value)) echo '>',htmlspecialchars($value),"</$tag>\n";   
                else echo ">\n",XML_serialize($value, $level+1),str_repeat("\t", $level),"</$tag>\n";   
            }   
    reset($data);   
    if($level == 0){ $str = &ob_get_contents(); ob_end_clean(); return $str; }   
}   

class XML{    
    var $parser;   #a reference to the XML parser    
    var $document; #the entire XML structure built up so far    
    var $parent;   #a pointer to the current parent - the parent will be an array    
    var $stack;    #a stack of the most recent parent at each nesting level    
    var $last_opened_tag; #keeps track of the last tag opened.    
  
    function XML(){    
         $this->parser = &xml_parser_create();    
        xml_parser_set_option(&$this->parser, XML_OPTION_CASE_FOLDING, false);    
        xml_set_object(&$this->parser, &$this);    
        xml_set_element_handler(&$this->parser, 'open','close');    
        xml_set_character_data_handler(&$this->parser, 'data');    
    }    
    function destruct(){ xml_parser_free(&$this->parser); }    
    function & parse(&$data){    
        $this->document = array();    
        $this->stack    = array();    
        $this->parent   = &$this->document;    
        return xml_parse(&$this->parser, &$data, true) ? $this->document : NULL;    
    }    
    function open(&$parser, $tag, $attributes){    
        $this->data = ''; #stores temporary cdata    
        $this->last_opened_tag = $tag;    
        if(is_array($this->parent) and array_key_exists($tag,$this->parent)){ #if you've seen this tag before   
            if(is_array($this->parent[$tag]) and array_key_exists(0,$this->parent[$tag])){ #if the keys are numeric   
                #this is the third or later instance of $tag we've come across    
                $key = count_numeric_items($this->parent[$tag]);    
            }else{    
                #this is the second instance of $tag that we've seen. shift around   
                if(array_key_exists("$tag attr",$this->parent)){   
                    $arr = array('0 attr'=>&$this->parent["$tag attr"], &$this->parent[$tag]);   
                    unset($this->parent["$tag attr"]);   
                }else{   
                    $arr = array(&$this->parent[$tag]);   
                }   
                $this->parent[$tag] = &$arr;   
                $key = 1;   
            }   
            $this->parent = &$this->parent[$tag];   
        }else{   
            $key = $tag;   
        }   
        if($attributes) $this->parent["$key attr"] = $attributes;   
        $this->parent  = &$this->parent[$key];   
        $this->stack[] = &$this->parent;   
    }   
    function data(&$parser, $data){   
        if($this->last_opened_tag != NULL) #you don't need to store whitespace in between tags    
            $this->data .= $data;    
    }    
    function close(&$parser, $tag){    
        if($this->last_opened_tag == $tag){    
            $this->parent = $this->data;    
            $this->last_opened_tag = NULL;    
        }    
        array_pop($this->stack);    
        if($this->stack) $this->parent = &$this->stack[count($this->stack)-1];    
    }    
}    
function count_numeric_items(&$array){    
    return is_array($array) ? count(array_filter(array_keys($array), 'is_numeric')) : 0;    
} 

?>
